
A new
study, just published online in the prestigious New
England Journal of Medicine, was able to prove that diet – a tasty and rather easy to keep one at that – was able to reduce stroke and heart disease by 30
percent.
The study, led by Dr. Ramón Estruch from
Barcelona, Spain, involved 7447 people, aged 55 to 80, all at higher risk for heart
disease due to diabetes or at least 3 risk factors or heart disease, such
as obesity, smoking, high blood pressure, elevated levels of bad cholesterol,
or a family history of early heart disease.
Participants
were randomly assigned to one of 3 groups:
- Mediterranean diet supplemented with approximately 4 cups a week of
extra-virgin olive oil (OVOO);
- Mediterranean diet supplemented with an additional ounce daily of
walnuts, hazelnuts and almonds;
- Control group that was counseled to eat a low-fat diet that did not
include olive oil or nuts. This group received small nonfood gifts.
Both
Mediterranean diet groups were encouraged to consume olive oil, nuts, fresh
fruits and veggies (at least 5-a-day), legumes, white meat and wine in
moderation with meals, and discouraged from soft drinks, commercial bakery
goods such as pastries and sweets and red meat. Sofrito (a
sauce made with tomatoes, onions, garlic and herbs, slowly simmered with olive
oil) was also recommended – at least 2 servings a week.
The
control group was advised to eat low fat dairy, fruits and veggies (at least
5-a-day), lean fish and seafood, and discouraged from vegetable oils (including
olive oil), commercial bakery goods, nuts, fried foods, red and processed fatty
meat and fatty fish.
To
be fair, the study doesn’t really compare the Mediterranean diet to a low fat
one, because the control group didn’t really adhere to a low-fat diet – they
must have found it hard. So the comparison is really between a Mediterranean
diet and a ‘whatever goes’ diet.
Although
people in all 3 groups had similar diets before the study started, compliance
with the Mediterranean diet was good, and was verified not just by
participants’ report, but also by measuring urinary hydroxytyrosol, a marker of
olive oil intake, and blood alpha-linolenic acid, a marker of walnut
consumption.
The
participants were followed for the occurrence of heart attacks, strokes, and
death from heart disease. After an average follow up of almost 5 years, 288
such events happened. Both Mediterranean diet groups experienced 30 percent
less such events compared with the control group.
Quite
encouraging! Especially since neither group was given a low calorie diet, or
advised to lose weight – which could of course reduce heart disease and stroke
risk, but isn’t easy to do. As a matter of fact the Mediterranean diet with
OVOO group was encouraged to eat 4 tablespoons of the oil each day, which is
450 calories in OVOO alone! The Mediterranean diet with nuts group was supplied
with about 200 calories-a-day in walnuts almonds and hazelnuts.
What’s special about
this study?
The Mediterranean diet has shown its protective benefits against
several diseases in many studies. A meta-analysis in the American
Journal of Clinical Nutrition combined the findings of many prospective studies,
pooling more than 2 million people, and showed that greater adherence to a
Mediterranean diet – in line with pretty minor lifestyle changes, like eating a
good amount of fruits and some nuts – was associated with 8 percent reduction
in death, 10 percent reduction
in cardiovascular illness and cardiac
death, 6 percent reduction in cancer
and 13 percent reduction in neurodegenerative
diseases, such as Alzheimer’s, and to offer some protection from stroke and mild cognitive losses.
This study adds to previous evidence, and stands out due to its scientific
rigor – it is a large, randomized controlled clinical trial, in which people were
allocated by chance alone to eat in a certain way, were followed for a long
time and were compared to a control group. Its results were also so conclusive that the
trial was stopped early in order to report the results and allow the control
group to enjoy the benefits of the Mediterranean
treatment.
What’s the health-promoting ingredient in the
Mediterranean diet?
So what should it be? Should
we dip bread in olive oil twice a day or snack on almonds?
Let’s remember that this study tested the effects of a Mediterranean diet on heart disease and stroke. As much as we’d like to learn a
magic trick from its findings, we cannot conclude that avoiding commercially
baked goods, avoiding soda,
eating sofrito, replacing red meat with fish or nibbling walnuts
saves lives. The people in the study changed many eating habits during the
study period.
The Mediterranean diet is an
eating pattern, a total plan, and should adopted as one. We don’t
know which part of the package confers the most benefit, all we know is that the
pattern works as a whole; all parts of it are
probably beneficial, and it very well might be that they work in combination
with each other. The Mediterranean
lifestyle – allowing for leisurely food enjoyment and social interaction –
might be just as important.
I think the Mediterranean diet
would be worth adopting for the sheer pleasure of it, and the health benefits are
just another great reason to go Mediterranean.
But I’d stop short of the at-least-4-tablespoons-OVOO-daily
the participants in this study were advised to eat. Way to many calories –
leaves too little to play with if you’re also aiming for an energy balanced
diet.
Dr. Ayala